Generally, a rotary door has a structure in which one side surface of the door is fixedly installed inside a support frame of a door frame at which the door is installed, and a door hinge part having a rotating shaft is installed in such a fixing installation surface to allow the door to horizontally rotate, thereby allowing the door to be opened and closed.
Many products having various shapes and structures have been developed and used as such a door hinge part. When a general hinge part using the most widely used pin-type hinge rod is used, a vertical displacement due to a vertical load of a door does not generally occur as long as a hinge frame for supporting the hinge rod is not deformed and a fixing means for fixing the hinge frame to the door or the support frame of the door frame has sufficient strength. However, since strength against a rotational moment on a vertical surface which is generated between an upper end and a lower end of the door is weak, a size and strength of a hinge joint part and a size and strength of a fixing means (an anchor) thereof should also be increased when the door becomes bigger, and thus it is difficult for the door to become bigger. In addition, since a response that satisfies a customer requirement for minimizing and slimming a cross-sectional dimension of the door (or a cross-sectional dimension of the door frame for supporting a window constituting the door) while enlarging a size of the door and a an increase of the size of the fixing means (the anchor) conflict with each other, there is a limit in solving the problem.
A gear hinge part (a gear hinge joint) illustrated in FIGS. 1 to 12 and having a structure different from that of the general hinge part using the pin-type hinge rod has been developed and used as a structure which may minimize the rotational moment generated on the vertical surface of the door between the upper end and the lower end of the door according to a tendency of a door to be large.
Hereinafter, to facilitate an understanding of the present invention, a detailed configuration of the gear hinge part and usage examples of a rotary door using the same will be described first.
In a rotary door 100U illustrated in FIGS. 1 to 3, a first support bracket 31 forming a gear hinge part 30 is fixedly connected to one vertical frame of a door support frame 10 of a door frame by a screw 30a, and a second support bracket 32 forming the gear hinge part 30 is fixedly connected to one side surface of a door 20 by the screw 30a, and gear parts 31a and 32a which are formed longitudinally are respectively provided at surfaces of the first support bracket 31 and the second support bracket 32 that face each other to be engaged with each other, and a rotation support frame 33 (referring to FIG. 3) which supports the gear parts 31a and 32a at a rear side thereof between the first support bracket 31 and the second support bracket 32 is provided so that the first support bracket 31 and the second support bracket 32 are hinge-rotated while the gear parts 31a and 32a, of the first support bracket 31 and the second support bracket 32 are maintained in an engaged state with each other and gear tooth portions thereof that are engaged with each other are changed.
Meanwhile, the gear hinge part 30 has a planar rotation structure which provides a high resisting force against the rotational moment and a smooth rotational action as illustrated in FIGS. 4 and 7. As illustrated in FIG. 4, hinge shaft protruding portions 33a formed to be bent from both ends of the rotation support frame 33 are rotatably inserted into rotating shaft support pockets 31b and 32b formed at a side that opposes the gear parts 31a and 32a provided at one end of each of the first support bracket 31 and the second support bracket 32 to be engaged with each other. And as illustrated in FIGS. 5 and 6, the first support bracket 31 and the second support bracket 32 are interlocked with each other to be shaft-rotated about the hinge shaft protruding portions 33a formed at both of the ends of the rotation support frame 33. For example, when the first support bracket 31 is fixed to a side of the support frame 10 of the door frame and the second support bracket 32 is fixed to a side of the door 20, the second support bracket 32 is rotated relative to the fixed first support bracket 31, as illustrated in FIGS. 5 to 7.
Furthermore, in a restriction of an axial rotation of the second support bracket 32, as illustrated in FIG. 7, when outer corners of the bent portions formed at both of the ends of the rotation support frame 33 are accommodated in the rotating shaft support pockets 31b and 32b that are formed at outer side surfaces of the first support bracket 31 and the second support bracket 32, which are rotated outward, excessive rotation thereof is no longer allowed.
The structure in FIGS. 4 to 7 is an example in which the second support bracket 32 can be rotated by about 180 degrees with respect to the first support bracket 31.
As illustrated in FIG. 8, the gear parts 31a and 32a which are longitudinally formed at both sides of the first support bracket 31 and the second support bracket 32 to be rotated and folded, and the rotation support frame 33, which supports the rotation of the gear parts 31a and 32a while the gear parts 31a and 32a are engaged with each other, allow smooth rotation between the first support bracket 31 and the second support bracket 32 on a horizontal plane and also provide a structure in which gear teeth, which are longitudinally formed to be long, are engaged with each other. Accordingly, even when the rotational moment generated on the vertical surface of the door between the upper end and the lower end of the door is increased due to a large size of the door 20, it is possible to sufficiently respond to the increased rotational moment, thereby providing structural stability which may minimize the possibility of a distortion phenomenon in an installation direction or position of the door.
Meanwhile, as illustrated in FIG. 9, the first support bracket 31 and the second support bracket 32, which are rotated while being engaged with each other by the gear parts 31a and 32a longitudinally formed at both sides thereof, may have a cross-sectional structure in which the second support bracket 32 that is fixedly connected to the side of the door 20 may be longitudinally displaced with respect to the first support bracket 31 that is fixedly connected to the side of the support frame 10 of the door frame. Therefore, to prevent this, openings 31c and 32c are respectively formed at the first support bracket 31 and the second support bracket 32 to face each other as illustrated in FIGS. 10 and 11, and a vertical hooking tool 34 is commonly inserted into the openings 31c and 32c that face each other and then fixed to an inner surface of the rotation support frame 33 through a fastening hole 35, as illustrated in FIGS. 10 and 11, and one end of the hooking tool 34 is geometrically matched with and accommodated in an inner space of the rotation support frame 33 and thus forms the gear hinge part 30.
An upper surface and a lower surface of the vertical hooking tool 34, which is provided to restrict the longitudinal displacement generated between the first support bracket 31 and the second support bracket 32 and also to support a vertical load, support cross sections of portions of the gear parts 31a and 32a of the first support bracket 31 and the second support bracket 32 at which the openings 31c and 32c are formed while being rubbed thereby when the door is rotated to be opened and closed, and thus are formed of a synthetic resin material which has a low friction coefficient and prevents a friction noise, unlike the first support bracket 31 and the second support bracket 32 generally formed of a metal material such as an aluminum alloy material.
However, in an actual situation in which the large-sized door 20 is installed at the support frame 10 of the door frame through the above-mentioned gear hinge part 30, as illustrated in FIG. 12, a downward displacement induced on the second support bracket 32 fixedly connected to the side of the door 20 by a weight W of the door 20 increases a friction force at a cross section contacting the vertical hooking tool 34, and thus friction noise is excessively generated when the door is rotated to be opened and closed. There is a problem in that it is difficult to avoid friction noise generated at the large-sized door with only the above-mentioned material solution.
Of course, the friction force at the cross section contacting the vertical hooking tool 34 may be reduced by lifting the door 20 fixed to the second support bracket 32 using various types of well-known lifting devices that use a hydraulic device or the like, and thus applying an upward displacement to the second support bracket. However, it is almost impossible to precisely adjust a height in a range of 0.1 mm to 0.5 mm using such lifting devices, and excessive expense is entailed in making it possible.
Until now, the problems in the related art related to a door hinge of a rotary door have been described focusing on the example in which the gear hinge part is used. As long as a structure in which a vertical displacement or distance may occur between components forming a door hinge part of a rotary door is provided, substantially the same technical problems as those in the gear hinge part will be generated even when a detailed configuration of the hinge part is changed.